The present invention relates to a power supply unit for a fire detector.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Fire detectors usually have a battery for power supply. It has been noticed that in approximately two-thirds of all cases of fire in the USA where people were killed and where the respective building had a fire detector, the battery of the respective fire detector had an insufficient charge state in order to ensure the function of the fire detector or there simply was none.
It is known to supply a fire detector via a power supply network such as the 230 V AC network with power. However, according to the relevant European norm EN 14604 it is required to have a power supply that is independent of the power supply network in order to ensure the operation of the fire detector even in the case of a loss of the power supply via the power supply network.
Power supply units for a fire detector are therefore known which in addition to a transformer and a rectifier further comprise a rechargeable battery as well as a charging and monitoring circuit. The disadvantageous aspect in such power supply units is that only very complex charging and monitoring circuits are capable of ensuring the life of a rechargeable battery over a period of approximately ten years.
It would therefore be desirable and advantageous to address prior art shortcomings and to enable an enhanced and reliable functional readiness of a fire detector in a simple manner.